package com.example.yckjbigdataservice.utils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Properties;

/**
 * kafka进行Kerberos登录认证
 */
public class KafkaLoginUtil {
    private static final Logger LOG = LoggerFactory.getLogger(KafkaLoginUtil.class);

    /**
     * no JavaDoc
     */
    public enum Module {
        KAFKA("KafkaClient"),
        ZOOKEEPER("Client"),
        Elasticsearch("EsClient");
        
        private String name;
        
        private Module(String name)
        {
            this.name = name;
        }
        
        public String getName()
        {
            return name;
        }
    }
    
    /**
     * line operator string
     */
    private static final String LINE_SEPARATOR = System.getProperty("line.separator");
    
    /**
     * jaas file postfix
     */
    private static final String JAAS_POSTFIX = ".jaas.conf";
    
    /**
     * is IBM jdk or not
     */
    private static final boolean IS_IBM_JDK = System.getProperty("java.vendor").contains("IBM");
    
    /**
     * IBM jdk login module
     */
    private static final String IBM_LOGIN_MODULE = "com.ibm.security.auth.module.Krb5LoginModule required";
    
    /**
     * oracle jdk login module
     */
    private static final String SUN_LOGIN_MODULE = "com.sun.security.auth.module.Krb5LoginModule required";
    
    /**
     * Zookeeper quorum principal.
     */
    public static final String ZOOKEEPER_AUTH_PRINCIPAL = "zookeeper.server.principal";
    
    /**
     * java security krb5 file path
     */
    public static final String JAVA_SECURITY_KRB5_CONF = "java.security.krb5.conf";
    
    /**
     * java security login file path
     */
    public static final String JAVA_SECURITY_LOGIN_CONF = "java.security.auth.login.config";
    
    /**
     * 设置jaas.conf文件
     * 
     * @param principal
     * @param keytabPath
     * @throws IOException
     */
    public static void setJaasFile(String principal, String keytabPath, String appPortName)
        throws IOException {
        String jaasPath =
            //new File(System.getProperty("java.io.tmpdir"))
                new File(System.getProperty("user.dir"))
                    + File.separator +
                        //System.getProperty("user.name")
                        "jaas"
                        + File.separator
                        +appPortName
                + JAAS_POSTFIX;
        LOG.info("jaasPath 路径"+jaasPath);
        createFileWithDirs(jaasPath);
        // windows路径下分隔符替换
        jaasPath = jaasPath.replace("\\", "\\\\");
        // 删除jaas文件
        deleteJaasFile(jaasPath);
        writeJaasFile(jaasPath, principal, keytabPath);
        System.setProperty(JAVA_SECURITY_LOGIN_CONF, jaasPath);
    }
    public static void createFileWithDirs(String filePath) throws IOException {
        File file = new File(filePath);

        // 如果文件不存在
        if (!file.exists()) {
            // 创建父目录
            File parentDir = file.getParentFile();
            if (parentDir != null && !parentDir.exists()) {
                boolean created = parentDir.mkdirs(); // 创建多级目录
                if (!created) {
                    throw new IOException("Failed to create directories: " + parentDir.getAbsolutePath());
                }
            }

            // 创建文件
            boolean newFile = file.createNewFile();
            if (!newFile) {
                throw new IOException("Failed to create file: " + filePath);
            }
        }
    }
    
    /**
     * 设置zookeeper服务端principal
     * 
     * @param zkServerPrincipal
     * @throws IOException
     */
    public static void setZookeeperServerPrincipal(String zkServerPrincipal)
        throws IOException {
        System.setProperty(ZOOKEEPER_AUTH_PRINCIPAL, zkServerPrincipal);
        String ret = System.getProperty(ZOOKEEPER_AUTH_PRINCIPAL);
        if (ret == null)
        {
            throw new IOException(ZOOKEEPER_AUTH_PRINCIPAL + " is null.");
        }
        if (!ret.equals(zkServerPrincipal))
        {
            throw new IOException(ZOOKEEPER_AUTH_PRINCIPAL + " is " + ret + " is not " + zkServerPrincipal + ".");
        }
    }
    
    /**
     * 设置krb5文件
     * 
     * @param krb5ConfFile
     * @throws IOException
     */
    public static void setKrb5Config(String krb5ConfFile)
        throws IOException {
        System.setProperty(JAVA_SECURITY_KRB5_CONF, krb5ConfFile);
        String ret = System.getProperty(JAVA_SECURITY_KRB5_CONF);
        if (ret == null)
        {
            throw new IOException(JAVA_SECURITY_KRB5_CONF + " is null.");
        }
        if (!ret.equals(krb5ConfFile))
        {
            throw new IOException(JAVA_SECURITY_KRB5_CONF + " is " + ret + " is not " + krb5ConfFile + ".");
        }
    }
    
    /**
     * 写入jaas文件
     * 
     * @throws IOException
     *             写文件异常
     */
    private static void writeJaasFile(String jaasPath, String principal, String keytabPath)
        throws IOException {
        FileWriter writer = new FileWriter(new File(jaasPath));
        try
        {
            writer.write(getJaasConfContext(principal, keytabPath));
            writer.flush();
            ESLoginUtil.writeFlag = true;
            HbaseLoginUtil.writeFlag = true;
            HbaseLoginUtil.jaasPath = jaasPath;

        }
        catch (IOException e)
        {
            throw new IOException("Failed to create jaas.conf File");
        }
        finally
        {
            writer.close();
        }
    }
    
    private static void deleteJaasFile(String jaasPath)
        throws IOException {
        File jaasFile = new File(jaasPath);
        if (jaasFile.exists())
        {
            if (!jaasFile.delete())
            {
                throw new IOException("Failed to delete exists jaas file.");
            }
        }
    }
    
    private static String getJaasConfContext(String principal, String keytabPath) {
        Module[] allModule = Module.values();
        StringBuilder builder = new StringBuilder();
        for (Module modlue : allModule)
        {
            builder.append(getModuleContext(principal, keytabPath, modlue));
        }
        return builder.toString();
    }
    
    private static String getModuleContext(String userPrincipal, String keyTabPath, Module module) {
        StringBuilder builder = new StringBuilder();
        if (IS_IBM_JDK) {
            builder.append(module.getName()).append(" {").append(LINE_SEPARATOR);
            builder.append(IBM_LOGIN_MODULE).append(LINE_SEPARATOR);
            builder.append("credsType=both").append(LINE_SEPARATOR);
            builder.append("principal=\"" + userPrincipal + "\"").append(LINE_SEPARATOR);
            builder.append("useKeytab=\"" + keyTabPath + "\"").append(LINE_SEPARATOR);
            builder.append("debug=true;").append(LINE_SEPARATOR);
            builder.append("};").append(LINE_SEPARATOR);
        } else {
            builder.append(module.getName()).append(" {").append(LINE_SEPARATOR);
            builder.append(SUN_LOGIN_MODULE).append(LINE_SEPARATOR);
            builder.append("useKeyTab=true").append(LINE_SEPARATOR);
            builder.append("keyTab=\"" + keyTabPath + "\"").append(LINE_SEPARATOR);
            builder.append("principal=\"" + userPrincipal + "\"").append(LINE_SEPARATOR);
            builder.append("useTicketCache=false").append(LINE_SEPARATOR);
            builder.append("storeKey=true").append(LINE_SEPARATOR);
            builder.append("debug=true;").append(LINE_SEPARATOR);
            builder.append("};").append(LINE_SEPARATOR);
        }
        
        return builder.toString();
    }

    public static void securityPrepare(String principal, String keyTabFilePath, String krb5FilePath ,String appPortName) throws IOException {
        //String filePath = System.getProperty("user.dir") + File.separator + "src" + File.separator + "main" + File.separator + "resources" + File.separator;
        //String krbFile = filePath + "krb5.conf";
        //String userKeyTableFile = filePath + keyTabFile;

        // windows路径下分隔符替换
        keyTabFilePath = keyTabFilePath.replace("\\", "\\\\");
        krb5FilePath = krb5FilePath.replace("\\", "\\\\");

        KafkaLoginUtil.setKrb5Config(krb5FilePath);
        KafkaLoginUtil.setZookeeperServerPrincipal("zookeeper/hadoop.hadoop.com");
        KafkaLoginUtil.setJaasFile(principal, keyTabFilePath, appPortName);
    }

    /**
     * Check security mode
     * krbFilePath  kafkaSecurityMode文件存放路径
     * @return boolean
     */
    public static Boolean isSecurityModel(String krbFilePath) {
        Boolean isSecurity = false;
        //String krbFilePath = System.getProperty("user.dir") + File.separator + "src" + File.separator + "main" + File.separator + "resources" + File.separator + "kafkaSecurityMode";

        Properties securityProps = new Properties();

        // file does not exist.
        if (!isFileExists(krbFilePath)) {
            return isSecurity;
        }

        try {
            securityProps.load(Files.newInputStream(Paths.get(krbFilePath)));

            if ("yes".equalsIgnoreCase(securityProps.getProperty("kafka.client.security.mode")))
            {
                isSecurity = true;
            }
        } catch (Exception e) {
            LOG.info("The Exception occured : {}.", e);
        }

        return isSecurity;
    }

    /*
     * 判断文件是否存在
     */
    private static boolean isFileExists(String fileName) {
        File file = new File(fileName);

        return file.exists();
    }
}
